第1个回答 2012-03-14
《英语基础词汇用法词典》认为：表示“在运动场上”或“在操场上”，playground前既可用介词in也可用介词on，但以用in为普通，并举如下：
The children were all in [on] the playground. 孩子们都在操场上。
They are playing baseball in the playground. 他们在运动场上打棒球。
The sports meeting was held on the playground. 运动会在操场上举行。